Build and ship projects

Turning skills into finished, shareable work: scoping, JSON and APIs, dependencies, configuration, a good README and publishing on GitHub.

Scoping a small project

Also called MVP, minimum viable product, milestones

What: Cutting an idea down to the smallest version that solves one real problem end to end, then splitting it into a handful of milestones.
Why: Finished small projects teach more and show more than ambitious unfinished ones.
Example: Not "a personal finance app", but "a command-line tool that reads my bank CSV and prints spending per category per month". Milestones: parse the CSV, categorise, total, print, test, README.

Watch out

Starting with login, a database and a UI before the core logic works at all.

Reading and writing JSON

Also called JSON, serialisation, parsing JSON, JSON.parse

What: JSON is a text format for objects, arrays, strings, numbers, booleans and null. Serialising turns your data into JSON; parsing turns JSON back into data.
Why: It is how most APIs and many config and save files exchange data. Python, JavaScript and C# ship a JSON library; Java and C++ usually add Jackson or nlohmann/json.

C++

#include <nlohmann/json.hpp>
using json = nlohmann::json;

std::ifstream in{"ledger.json"};
json data = json::parse(in);
in.close();
data["entries"].push_back(
    json{{"amount", 12.5}, {"note", "lunch"}});
std::ofstream out{"ledger.json"};
out << data.dump(2);

Watch out

Trusting parsed JSON blindly: fields can be missing, null or the wrong type, so validate before use.

Calling a public API

Also called HTTP, REST API, fetch, HttpClient, requests

What: Sending an HTTP request (usually GET or POST) to a web service and reading its response, typically a status code plus a JSON body.
Why: Public APIs give a small project real data (weather, books, transport) without building a backend.

C++

#include <cpr/cpr.h>
#include <nlohmann/json.hpp>

auto res = cpr::Get(
    cpr::Url{"https://jsonplaceholder.typicode.com/todos/1"},
    cpr::Timeout{10000});
if (res.status_code != 200) {
  throw std::runtime_error("HTTP error");
}
auto todo = nlohmann::json::parse(res.text);
std::cout << todo["title"] << '\n';

Watch out

Assuming the call succeeds: set a timeout, check the status code and handle the network being down.

CMake

Also called CMakeLists.txt, build system, vcpkg, Conan

What: CMake describes how to build a C++ project in CMakeLists.txt and generates the real build files for your platform. Package managers such as vcpkg or Conan supply libraries.
Why: It is the de facto standard for C++ projects, so others can build yours on Linux, macOS or Windows with the same two commands.

CMAKE

cmake_minimum_required(VERSION 3.25)
project(ledger CXX)
set(CMAKE_CXX_STANDARD 20)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

add_executable(ledger src/main.cpp src/pricing.cpp)
target_compile_options(ledger PRIVATE -Wall -Wextra)

# cmake -S . -B build && cmake --build build

Watch out

Committing the generated build folder, or hard-coding compiler paths that only exist on your machine.

Configuration and secrets

Also called environment variables, .env, API keys

What: Settings that change between machines (API keys, URLs, file paths) are read from environment variables or a local config file instead of being written into the code.
Why: It keeps secrets out of Git and lets the same code run on your laptop, a friend's machine and a server.

C++

const char* key = std::getenv("WEATHER_API_KEY");
if (key == nullptr) {
  throw std::runtime_error("WEATHER_API_KEY not set");
}
std::string api_key{key};

Watch out

Committing an API key: bots scan GitHub within minutes, so revoke the key at once, since deleting the commit is not enough.

Writing a README

Also called README.md, project documentation

What: The front page of a repository: what the project does and for whom, a demo, how to install, run and test it, how it works and its known limits.
Why: It is the first thing a reviewer, teammate or employer reads, and often the only thing. A project nobody can run might as well not exist.

MARKDOWN

# Ledger
One sentence: what it does and who it is for.

## Demo
A GIF or two screenshots.

## Getting started
Requirements, then install and run commands.

## Running tests
## How it works
## Limitations and next steps

Watch out

Leaving the default template, or skipping the exact commands to run the project from a fresh clone.

Publishing on GitHub

Also called gh repo create, licence, portfolio

What: Pushing a project to a public GitHub repository with a README, a licence, a .gitignore and a clean history of meaningful commits.
Why: It backs your work up, makes it easy to share, and shows how you work, not just what you built.

Shell

git remote add origin https://github.com/you/ledger.git
git branch -M main
git push -u origin main

gh repo create ledger --public --source=. --push

Watch out

Pushing one "initial commit" containing the entire finished project, which hides how it was built.

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